// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System.Runtime.InteropServices;

internal static partial class Interop
{
    internal static partial class Sys
    {
        internal enum SysLogPriority : int
        {
            // Priorities
            LOG_EMERG       = 0,        /* system is unusable */
            LOG_ALERT       = 1,        /* action must be taken immediately */
            LOG_CRIT        = 2,        /* critical conditions */
            LOG_ERR         = 3,        /* error conditions */
            LOG_WARNING     = 4,        /* warning conditions */
            LOG_NOTICE      = 5,        /* normal but significant condition */
            LOG_INFO        = 6,        /* informational */
            LOG_DEBUG       = 7,        /* debug-level messages */
            // Facilities
            LOG_KERN        = (0<<3),   /* kernel messages */
            LOG_USER        = (1<<3),   /* random user-level messages */
            LOG_MAIL        = (2<<3),   /* mail system */
            LOG_DAEMON      = (3<<3),   /* system daemons */
            LOG_AUTH        = (4<<3),   /* authorization messages */
            LOG_SYSLOG      = (5<<3),   /* messages generated internally by syslogd */
            LOG_LPR         = (6<<3),   /* line printer subsystem */
            LOG_NEWS        = (7<<3),   /* network news subsystem */
            LOG_UUCP        = (8<<3),   /* UUCP subsystem */
            LOG_CRON        = (9<<3),   /* clock daemon */
            LOG_AUTHPRIV    = (10<<3),  /* authorization messages (private) */
            LOG_FTP         = (11<<3),  /* ftp daemon */
            // Between FTP and Local is reserved for system use
            LOG_LOCAL0      = (16<<3),  /* reserved for local use */
            LOG_LOCAL1      = (17<<3),  /* reserved for local use */
            LOG_LOCAL2      = (18<<3),  /* reserved for local use */
            LOG_LOCAL3      = (19<<3),  /* reserved for local use */
            LOG_LOCAL4      = (20<<3),  /* reserved for local use */
            LOG_LOCAL5      = (21<<3),  /* reserved for local use */
            LOG_LOCAL6      = (22<<3),  /* reserved for local use */
            LOG_LOCAL7      = (23<<3),  /* reserved for local use */
        }

        /// <summary>
        /// Write a message to the system logger, which in turn writes the message to the system console, log files, etc. 
        /// See man 3 syslog for more info
        /// </summary>
        /// <param name="priority">
        /// The OR of a priority and facility in the SysLogPriority enum to declare the priority and facility of the log entry
        /// </param>
        /// <param name="message">The message to put in the log entry</param>
        /// <param name="arg1">Like printf, the argument is passed to the variadic part of the C++ function to wildcards in the message</param>
        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_SysLog")]
        internal static extern void SysLog(SysLogPriority priority, string message, string arg1);
    }
}